Which part are you having problems with? I got it, and we know that you are a thousand times better at DE's than me, so I must be overlooking something to. The 1-z^2 is obvious right? and the rest...so which part?

Which part are you having problems with? I got it, and we know that you are a thousand times better at DE's than me, so I must be overlooking something to. The 1-z^2 is obvious right? and the rest...so which part?

No wonder you are confused. I am confused. Typical physics "math" garbage what does "change variable from cos@ to z" is even supposed to mean? It is stuff like this made me spend much time translating physics "math" into formal understanding. Anyway, I guess I know what you have to do - whether it actually makes any sense I live it to you to decide, because it makes no sense to me (eventhough I have experience in trying to understand what the problem is asking).

Instead of differentiating a second time wrt theta, differentiate wrt z and use the chain rule. Then you have d/dz [....] times dz/dtheta = d/dz [....] times (- sin theta).

And sin^2 theta = 1 - cos^2 theta = (1 - z^2) .....

Originally Posted by ThePerfectHacker

No wonder you are confused. I am confused. Typical physics "math" garbage what does "change variable from cos@ to z" is even supposed to mean? It is stuff like this made me spend much time translating physics "math" into formal understanding. Anyway, I guess I know what you have to do - whether it actually makes any sense I live it to you to decide, because it makes no sense to me (eventhough I have experience in trying to understand what the problem is asking).